As a rule, I try not to buy sets that are priced over 10 cents per piece. There are exceptions though, because extra minifigs will sometimes offset the piece to price ratio in smaller sets, and they're the reason for buying the smaller sets in the first place.

It seems overpriced because it's much bigger than you think it is. Standard Lego designs show all their features on the surface, so it's easy to see how much is going on when you look at the cover photo. The fan-based designs have all the detail on the inside, so from the cover photos they look less impressive than they actually are.